Ok, this seems a dead ringer for a done before thread so forgive me. I tried to search but came up with nothing, if you find a previous thread please educate me and tell me what you searched under rather than just linking. Thanks.
Anyway, question’s probably obvious enough. I mean black coffee must be close to 100 degrees which would make a real mess of seemingly tougher skin on other body areas but we routinely throw the stuff down our necks.
And lips too, i mean they don’t seem like the hardiest of things yet they seem to survive a lot. The mouth i’m thinking is wet with saliva so maybe that stops burning a bit, but what about lips?
I suspect a lot of it is precisely because we do routinely drink hot liquids. Parts of the body can adapt to considerable extremes of temperature over time. It’s why we can go out in cold weather with our faces uncovered, but would succumb to hypothermia if we went out in the same cold without clothes to keep the rest of our bodies warm.
Let me assure you, if you’re drinking liquids near to boiling, you will know it immediately, and you’ll stop! Foods over 60 degrees celsius constitute a burn hazard for the skin and mucous membranes.
Typical drinking temperature of coffee varies, but is considered to be around 45 degrees celsius.
I suspect that’s mostly just due to the total amount of exposed surface. I suspect that going out with your face covered but a face-sized area of your belly exposed would be no worse, except that that would be awkward clothing. And we haven’t controlled fire (and hence drank hot liquids) for a long enough time for evolution to make any significant difference, here.
I don’t know about that. It’s definitely true that some parts of the body are more sensitive to heat than others. Mothers of young children test the temperature of the baby’s bathwater with their elbows because their hands are too used to immersion in very hot water.
I know that, I wasn’t talking about evolution but the phenomenon of “getting used to” something, which operates over much shorter time scales.
Really? I did not know that. I don’t actually drink tea or coffee so i wouldn’t know, i just assumed that if you boil a kettle and pour straight away there can’t be that much of a temperature drop.
So, just to be clear, are you saying that the mouth is just the same as skin when it comes to actually burning? By that i mean, the temperature that causes injury is the same it’s just that the pain threshold’s are different.
I could buy that, anyone know for sure? Great care is taken not to give babies milk/food that is too hot for example, is there a gradual desensitisation with age? Or is this just cause babies are fragile anyway?
If i had never eaten/drank anything hot in my life would i have to go through this process now before i could handle food at normal temperature?
100 degree Fahrenheit liquids aren’t really hot at all. That’s just above human body temperature. If you touched something that hot, it would feel noticeably warm, but it certainly wouldn’t burn you. Same if you drank it… it would feel warm, but unable to burn. Hotter temperatures most certainly can burn your mouth, as I’m sure many people can attest to. When something’s really hot, though, people start by taking careful little sips – if it’s too hot, it might scald very slightly, and then you wait for the drink to cool more.
If anything, I’d guess that the mouth was more sensitive to heat than most other areas of skin.
Since the poster in question is from Scotland and later talks about pouring water right out of a kettle, I assume he was talking about Celcius, as water boils at 100 C.
I drink coffee black (uncooled by cream) and hot. But for the first few minutes I sip it over the lip of the mug, drinking less than a teaspoonful at a time. The small mass of hot liquid, plus the increased surface area, keep the stuff cool enough not to burn my mouth. On the few occasions I have tried sipping it through a straw, I’ve spit it out or gotten blisters. Or both.
Here’s a related question: why do we happily gobble down hot pizza, not noticing the pizza related palate blisters until after the meal?
I for one usually notice when pizza burns me, though I am invariably caught off-guard by the gradual sloughing of skin between my two middle upper incisors and my upper molars. I’d guess offhand that when we’re eating pizza, we’re concentrating on the food rather than what’s happening to our mouths.
I eat a lot of hot pizza and drink a lot of hot coffee. I’m going to agree with the “getting used to it” theory, since I gradually realized over many years that what I eat and drink easily many people find scalding. I’m done with a cup of coffee before my wife has her first sip; if she tried to drink mine she would burn her mouth, and if I drank hers I’d puke because cold coffee disgusts me. … In addition, I think that I have unconsiously perfected a technique for dealing with hot foods and drinks. Like nelsonholly describes, I sip coffee in such a way that it cools off enough not to burn my mouth when I drink it. I eat hot pizza in little easily cooled bites until it cools enough to eat bigger bites. Furthermore, I can move hot food around in my mouth “hot potato” fashion so it doesn’t sit in any one spot long enough to burn it.
Anyway, that’s my experience. I hate to answer GQ questions with anecdotes but my experience leads me to conclude that the reason the mouth seems insensitive to heat is because a) we get used to hot things there, and b)we have perfected techniques of not burning our mouths. While hot things on other parts of our body just sit there and burn us.
I personally am the other end of the spectrum, I am the biggest hot food pansy in existence. Hot beverages, fresh from the oven pizza, I can’t go there. I often have to wait a few min or in the case of a hot beverage toss in a small ice cube to take the edge off.
While it just changes the question (to “Why are some mouths so insensitive to heat?”) I’ll chime in and say that it depends on the person. I CAN’T drink freshly made hot tea - it hurts if I try. I have to let it cool for a while before I drink it.
As the *father * of young children who has drawn many a bath, I will say that your hands do not get used to temperatures. The reason that you test the water with part of your body other than your hands (never heard the elbow before, I used forearms) is that the hands vary widely in temperature because they gain and lose heat quickly, being at the extremity and having a high surface area:volume. If you put one hand in the fridge for a while and the other in an oven, they will perceive the temperature of the same water quite differently.
Consider a hot cup of coffee or tea, it is often painful to hold the cup directly, that is why most cups have handles. Dispite this it is easy enough to drink the liquid therein.
So the mouth can cope with liquids too hot to touch with the hand comfortably.
Is this something humans have developed to cope with hot food (something outside the experience of almost all the rest of the animal kingdom). Or do we build up a tollerance over time (somewhat like a Chef’s ‘asbestos’ fingers)?
After you pour from the kettle, you either add cold milk, or you wait until it cools to drink. Drinking right out of the boiling kettle would burn your mouth.
Related question: When I was young and would be ice skating or playing hockey, if I drank hot chocolate purchased from the stand at the arena, I would almost always burn my mouth. I would wait until I thought it had cooled, but still always burned my mouth. Was I just unlucky and the arena always had super-heated hot chocolate? Or did the brisk exercise in the cold arena cause the relative temperature in my mouth to drop so that the heat of the hot chocolate seemed more extreme?
Assuming that it was made from a commercial sort of hot chocolate making machine, I would guess that you were receiving a beverage that could have just been extremely hot, such as the coffee that McDonald’s was selling that was at a much higher temperature than one would normally expect coffee to be at.
Many years ago, I designed a bunch of equipment for a neurobiologist who was studying pain. One of my torture devices (er, I mean highly sophisticated pieces of lab equipment… ahem) was designed to test hot and cold pain thresholds using a probe that could go from about 5 deg C to about 50 deg C and anywhere in between in about 2 seconds max, and would be accurate to the nearest 0.5 deg C. With the probe placed against skin on the arm or hand, most people say “ouch” at about 42 or 43 deg C. I never thought to stick the probe in my mouth, or any other orifice for that matter.
There are two different pain receptors for heat in your skin. The first one (TRPV1) kicks off at a little under 45 deg C. The second doesn’t kick in until a bit above 50 deg C. The first one is also sensitive to capsaicin, which is the chemical in hot chilli peppers that makes them “hot”. Anyone who has eaten hot chilli peppers will tell you quite certainly that you do indeed have these pain receptors in your mouth. Birds, by the way, don’t have these types of pain receptors and can eat hot peppers as much as they want without feeling the “hot” sensation from them.
I really don’t know why humans can tolerate coffee or tea that is 45 deg C. I’m wondering if it’s more of a simple thermodynamics thing instead of a chemical thing. Your mouth is full of saliva, etc. and the blood vessels are very close to the surface, so they could probably carry the heat away a lot quicker than they can in the skin of your arm. It could be that the skin inside your mouth isn’t heating up as quickly as the skin on your fingers as you are holding the coffee cup, for example. Just a WAG though.